A separator was devised by the Sanitary Devices Manufacturing Company in which the bag was held extended by a wire ring having a weighted rod passing out through the top of the separator attached thereto. When the bag became clogged the difference in pressure on the two sides would result in a tendency of the bag to collapse and the rod would be raised up out of the separator, indicating that cleaning was necessary, which could be easily accomplished by drawing the rod up and down a few times thus shaking the dust off the bag. This separator never came into general use, although its arrangement was ingenious and should have been easy to operate.
The great difficulty with all bags which must be cleaned periodically is that they are almost universally neglected even when there is a visual indicator to show the accumulation of dirt, and when it becomes necessary to manipulate a three-way cock in order to ascertain when this cleaning must be done it will seldom if ever be attended to. A bag that will clean itself, such as the Capitol Invincible, is shown in [Fig. 76].
The separator used by one manufacturer consists of a simple cylindrical tank into which the air is blown tangentially, with a screen near the top, the whole forming a base for the vacuum producer. This separator does not remove any but the heaviest dirt and is suitable for use only with a vacuum producer having very large clearances and in locations where the discharge of considerable dirt into the atmosphere is not objectionable.
Total Wet Separator.
—The only total wet separator which is in commercial use is manufactured by the American Rotary Valve Company. This separator is contained in the base of the vacuum producer and is provided with a screen near the point of entrance of the dust-laden air, which screen is cleaned by a mechanically-driven bristle brush. When the water in the separator becomes foul, the contents of the separator are discharged direct to the sewer by means of compressed air. If this separator receives proper attention it makes the most sanitary arrangement that has been introduced in the vacuum cleaning line to date. However, the separator should be emptied at frequent intervals or the volume of solid matter contained in the same will become so great that there will not be enough water present to flush the sewer and stoppage is likely. These separators are often neglected until the contents become of the consistency of mortar or molasses which is not a fit substance to discharge into a sewerage system.
There is still another form of apparatus used in connection with vacuum cleaning systems which should be called an emulsifier rather than a separator. That is the type used with the Rotrex and the Palm systems. The dust is mixed with water when it first enters the pump chamber, a screen being used to remove the lint and larger particles of dirt and then the mud produced by the combination of the dust and water is passed through the pump along with the air. The air and muddy water are separated on the discharge side of the vacuum producer. In many cases where the exhaust pipe is long, there is considerable back pressure on the discharge which is often sufficient to force the seals in traps on the sewerage system, allowing sewer gas to be discharged into the building in which the cleaning system is installed. No means are provided for automatically cleaning the screen used in these appliances and the author knows of cases where the screen has become so completely clogged with lint that its removal from the machine was necessary in order to render the operation of the cleaning tools possible.
When dry separators are used, the manual removal of the dry dirt accumulated is necessary and is an objectionable as well as unsanitary operation. The author considers that the ideal arrangement of separator would be one in which the dirt can all be emulsified with water and retained in the separator, only the air passing through the vacuum producer, and in which the contents of the separator would be discharged automatically to the sewer when the density of this mixture becomes as heavy as will readily run through the sewer. This discharge should be of sufficient volume to completely fill an ordinary house sewer in order to insure a thorough flushing of the drain, and should be discharged into the sewer under atmospheric pressure in order to guard against the forcing of water seals in any of the plumbing fixtures.
FIG. 77a. INTERIOR CONSTRUCTION OF DUNN VACUUM CLEANING MACHINE.
A separator of this type has recently been patented by E. D. Dunn, originator of the Dunn Locke system. It is illustrated in [Fig. 77a]. The action of the separator is as follows: After starting the motor and turning on a small quantity of water, a vacuum is produced in one tank and through a system of piping to the cleaning implement in use. The dust and dirt collected by the implement is saturated as it approaches the plant and in this saturated condition enters the bottom of a body of water in the tank.